This invention relates to improvements in thermic insulating covers for facade and the like walls, and more particularly to such thermic insulating covers which are internally ventilated by being provided with ventilation channels extending from a lower to an upper end zone of the cover over the entire height of the facade.
The thermic insulating cover may also be at the same time sound-absorbing.
It is well known to thermically insulate buildings by covering their facade with insulating plates made of foamed synthetic resin material which are provided with a system of internal ventilating channels or ducts. Typical examples of such internally ventilated covers for facades have been described in my Swiss Pat. No. 648,888 and my European patent application No. 84.810.196.0. The ducts can extend vertically or, preferably, diagonally, e.g. at an angle of inclination of 45.degree., and they can be interconnected where they intersect one another. The facade cover consists usually of a number of prefabricated cover panels which are affixed on the underlying wall layer of the building by various known methods.
A problem caused by such facade covers is that they are usually not difficultly inflammable but quite combustible, and especially by the fact that the ventilation channels which extend in their interior, for instance close to their external surface, from the foot zone of the covered facade to its top zone, produce a so-called "chimney effect" in case of fire, causing hot air to rise in them upwards and drawing fresh air into the system at the foot zone, thereby rapidly spreading a fire in lower storeys of a building to the higher ones and to its roof.
The fire protection of openings for tubes and cables in the walls of buildings by passing such tubes or cables through fire protective blocks having a surface covered by a heat-foamable hydrated potassium or sodium silicate optionally covered in turn by a metal layer such as an aluminum foil has been recommended by Flamex Ltd., Nassau, Bahama Islands in their German Offenlegungsschrift No. 21 62 251 published on June 20, 1973. Other thermally expandable sealants have been disclosed in U.S. Pat. No. 4,277,532, granted to Hubert Czepel et al on July 7, 1981. However, this sealant contains chlorinated hydrocarbon phenol-formaldehyde, resins and asbestos fibers and is therefore undesirable for the purposes of the flame barrier according to the invention.
U.S. Pat. Nos. 3,678,634 granted to Eugene H. Wise et al on July 25, 1972 and 4,221,092 granted to William L. Johnson on Sept. 9, 1980, deal with the problem of rendering the junction zones where thermoplastic pipes pass through walls and floors of buildings fire-retarding.